ORDER IL 



MOLLUSC A, 



The bodies of all this order are simple, and furnished with 

 limbs ; many of them are destitute of any coat or covering, 

 some are quite gelatinous, and others furnished vrith a crust 

 or shell, which differs in substance from the shells of Testa^ 

 ceous Animals, the latter being principally composed of car- 

 bonate of lime, and those of Crustaceous Animals, of phos- 

 phate of lime. But few of them are applicable to the uses 

 of Mankind. There are thirty-two genera in the order. 



* Mouth placed above » 



1 . Actinia, Body fixed, with a single terminal dilatable 



aperture^ surrounded with tentacula or cirri» 



2. Clava. Body fixed, with a single vertical dilatable apeV' 



ture^ surrounded with clavate tentacula. 



3. Pedicellaria. Body fixed, and furnished with a rigid 



peduncle. 



3, Mammaria. Body not affixed, smooth, wit a single 

 aperture^ without cirri. 



h. Ascidia. Body fixed, with two apertures^ one of which 

 is terminal, the other situated a little beneath. 



